1. Field of the Invention
The present invention relates to the application of coating constituents to form desired types of coatings on relatively large surface areas that characteristically are referred to as "traffic surfaces," typically roadway surfaces such as highways, streets, driveways, parking lots, runways, taxiways, and tarmacs that are of sufficient size to warrant the use of relatively large power operated machinery to dispense and mix coating constituents to form desired types of coating materials, and apply the mixed materials to form coatings of a desired character that are intended to protect, restore, and enhance traffic surface integrity.
More particularly, the present invention relates to a system for dispensing coating constituents onto a traffic surface, for mixing the dispensed constituents in situ on the the traffic surface, and for effecting a controlled application of the resulting coating by utilizing a novel and highly versatile apparatus that includes a plurality of rotary finishing units, with each of the rotary finishing units including a separate set of rotary applicator tools, with the tools of each set being mounted for rotation about a separate vertically extending axis, and with the sets of tools being rotated in tandem by a power drive system to enable a very large traffic surface area to be coated quickly, easily, and in a desired manner utilizing any of a wide variety of coating constituents to effect a coating application that has desired characteristics. 2. Prior Art
Two terms known to those skilled in the art are used herein and should be defined, for both of the terms can be interpreted relatively broadly or relatively narrowly, whereby their precise meanings can differ. The terms are "traffic surface" and "tandem." Both of these terms are used herein in a relatively broad sense rather than a relatively narrow sense.
The term "traffic surface" is used in a generic sense to refer to a wide class of substantially horizontal surfaces such as highways, streets, driveways, parking lots, runways, taxiways, tarmacs, floors of large garages and industrial buildings, loading dock decks, and the like that need to be coated from time to time to protect, restore, and enhance surface integrity.
The term "tandem" is used in a generic sense to indicate a cooperative mounting and operating relationship between and among sets of applicator tools that are rotated concurrently, whereby, for example, tandem sets of concurrently rotating applicator tools cooperate with each other so that the resulting mixing and application functions they perform tend to be enhanced by their concurrent and cooperative rotation. The term "tandem," as used in this document, is further intended to encompass a variety of relative positionings of the rotary finishing units (i.e., the sets of rotary tools), for example arrangements wherein the vertical axes of rotation of the sets of tools are spaced forwardly and rearwardly relative to a forward path of travel that is followed by the apparatus in moving across a traffic surface (and/or a transverse, side-by-side relationship of selected ones of these axes, etc.).
Because traffic surfaces are exposed to wear and often to the effects of the elements, they are subject to deterioration and periodically require the application of coatings to protect, restore, and enhance their integrity, and to thereby extend their useful lives. Some traffic surfaces should be coated when constructed, as by the application of a coating that seals the surface and thereby protects against water penetration that, in winter, can cause spalding or cracking. Many traffic surfaces require protective and reconditioning coatings periodically and/or after the surfaces have been subjected to a certain amount of use.
Due to the wide variety of materials that are used to form traffic surfaces, the wide range of uses to which traffic surfaces are subjected, and the many types of coating constituents that are available to protect against specific kinds of wear and deterioration, there has been a longstanding need for a highly versatile system for dispensing, mixing, and applying coatings to traffic surfaces. The need has been particularly pressing with respect to the protective coating of traffic surfaces of large area such as highways, airport runways, bridge roadways, and the like where manual dispensing, mixing, and application of coating constituents is utterly impractical.
While a variety of proposals have been made for apparatus to dispense, mix, and coat large traffic surfaces, most prior proposals have been characterized by drawbacks such as a lack of versatility of the apparatus to dispense, mix, and apply coating constituents of a wide range of kinds and types, and a lack of adjustability to enable coating applications to be made that differ in desired ways such as thickness and the degree to which the resulting coating conforms to the shape of the surface being coated (e.g., whether the coating tends to smooth or diminish surface irregularities). Indeed, the problems that are associated with efforts to provide a highly versatile traffic surface coating system have been deemed to be so extensive in character that it has become standard practice to design and build traffic surface coating apparatus such that it is intended to apply only a limited selection of coating constituents, with the apparatus being designed for use on only selected types of traffic surfaces.
A further drawback of most prior traffic surface coating apparatus proposals is that their components and systems are not readily adapted to be scaled upwardly or downwardly in size and capability to provide a complete line of highly versatile coating dispensing, mixing, and applicator machines. Stated in another way, a drawback of prior proposals for traffic surface coating apparatus resides in the fact that, while what has been proposed may serve its intended purpose within a limited range of functions for a specific size of machine and type of traffic surface, prior proposals are not well adapted for use with larger or smaller machines, for performing multiple coating functions or applying a variety of coating constituents, and/or for use in protectively coating other types of traffic surfaces. Rather, certain types of system proposals have been made for use in coating concrete sidewalks; others have been proposed for use in coating roofs of buildings; others for use in coating parking lot surfaces; and still other types of systems have been proposed for coating very large applications such as highways and airport runways -- with variations of many of these proposals being offered for use with specific different types of coating constituents.
In short, prior system proposals have not only been lacking in versatility with respect to the type of coating constituents and the type of traffic surface materials with which they are intended to be used, but also have been lacking in versatility from the viewpoint that the approaches they utilize to effect dispensing, mixing and application of coating constituents have not been found to be acceptable for use across a product line of coating apparatus ranging from small machines for relatively narrow coating applications such as sidewalks to large machines for vastly extensive coating applications such as highways and runways.
Still another drawback common to the vast majority of previous proposals for traffic surface coating apparatus is that the spreading and applicator tools used by the proposed machines are not well suited for treating surfaces which have significant surface variations or which require a repetitive blading action to effect proper feeding and/or troweling of material into and about large cracks. Stated in another way, the application tools used by the apparatus of most prior proposals are lacking in versatility and in capability to cope with traffic surface variations.
A further and significant limitation of prior applicator proposals is their inability to effectively admix in situ materials such as epoxy substances, fibrous, beaded, or heavy particulates, and/or quick-setting soluble substances to form uniform slurry compositions. 3. The Referenced Parent and Grandparent Cases
The referenced Grandparent Case addresses certain of the foregoing and other drawbacks of prior proposals by providing a novel and improved system that features a sufficient degree of versatility to enable its use in applying coatings to traffic surfaces of a wide range of sizes.
The referenced Parent Case addresses the need for a simple and inexpensive system for spreading and applying surface coating ingredients utilizing a machine that is manually maneuvered with ease and that is well suited to accommodate traffic surfaces of moderate size which have closely confined boundaries, changing contours, and/or significant surface irregularities.
The proposals of both of the Parent and Grandparent Cases utilize rotary applicator tools that are of a highly versatile character and that have an inherent capability to cope with significant variations of the surfaces on which coatings are being applied.